The New HCM 7th Edition

TRB has made the decision to officially release the next manual as HCM 7.0, with intent to have the electronic version available in time for the TRB 2022 Annual Meeting (print publication to follow soon thereafter). The decision to release an entirely new version of the HCM (as opposed to an HCM 6.1 update as previously discussed) is motivated by a number of key aspects, including:

• New Electronic Format - The HCM 7^th Edition breaks new ground in that it is the first edition of the HCM that will be available not only in bound, printed format, but also in two electronic formats (PDF and e-book) that are hyperlinked, searchable, and make the HCM truly “portable.” The electronic version also will make all of the Volume 4 chapters readily accessible for offline use.

• New and Expanded Procedures – The HCM 7^th Edition will formally incorporate significant additions or expansions to computational procedures:

o Guidance on application of HCM methods to determine capacity impacts of connected and automated vehicles (CAVs).

o A new network analysis method to evaluate spillback between freeways and urban streets, estimate travel time across facilities, and conduct lane-by-lane analysis for freeways.

o A new two-lane highways analysis method that offers an improved analysis of two-lane highway capacity and operational performance.

o Enhancements to existing pedestrian analysis methods at signalized intersections and uncontrolled crossings

• Significant Errata – The HCM 7^th Edition will address all errata and revisions from the HCM 6.

Together, these changes result in updates to more than one-third of the printed pages of the HCM 6, making it desirable to incorporate all updates into an entirely new version.

TRB hosted a webinar on "What is new in HCM7" at the annual meeting 2022. Click here to access the presentation.

New Corridor Methodology for HCM is now available

The draft final report for NCHRP 15-57 entitled as "Highway Capacity Manual Methodologies for Corridors Involving Freeways and Surface Streets" is now available to download.

The objective of this research project is to develop materials for the HCM in order to modify the freeway analysis methods and the urban street methods so that the effects of operations from one facility to the other can be evaluated. This report summarizes the entire research effort and provides the proposed new HCM Chapter (Chapter 38). The new methods produced can be used to evaluate operations along corridors that include both arterials and freeways. The methods can also evaluate the impact of spillback into freeways and into arterials from downstream facilities.